Asphalt cements have been used in pavement for several years. Conventionally, rubber has been added to asphalt cements to improve the low temperature flexibility and extensibility (ductility) and increase the summer temperature viscosity. Whereas addition of a rubber latex has resulted in significant improvement in some properties, the rubber solids have a tendency to phase separate in many hot asphalts and thus become an incompatible component. Therefore, there exists a need for modified asphalt cements which contain a rubber latex that is compatible with the asphalt cement and does not tend to phase separate over time.